Adverse reactions to medications are very common and five to ten percent of these reactions can represent a true allergic reaction. Reactions vary from mild to life-threatening and can manifest as anything from a mild rash up to a severe anaphylactic reaction. While any medication can cause a reaction, a few of the more common classes that can trigger a drug allergy include antibiotics, anti-seizure medications, and anti-inflammatory drugs.
Allergy skin testing is available to identify several of the more common drug allergies including local anesthetics and penicillin. In fact, eighty to ninety percent of patients with a history of a reaction to penicillin can receive it safely after appropriate testing. This can result in more appropriate treatment for patients with infections, avoiding broader spectrum antibiotics, and limiting the development of drug-resistant infections.
There are also certain medication exposures that are well known to cause a unique type of drug allergy response. Intravenous radiocontrast dye can cause a drop in blood pressure, flushing, and itching, while ACE inhibitors for blood pressure can cause cough and angioedema. Aspirin and NSAIDS can worsen respiratory disease and urticaria.